peters square to hear pope benedict give his penultimate angeles prayer. he asked for them to pray for him and the next pope. the pope is now going into a week-long lenten retreat. this is an annual tradition, and part of the lenten season. when he re-emerges, he will convene the last angelis prayer and then step down as the pontiff. it's not clear at this point when the meeting of the conclave, the meeting of 117 cardinals assembled to vote for the next pope will meet. however, a senior vatican spokesman on saturday said that, it could happen earlier than planned, before the 15th of march. i'm ben wedeman, cnn, reporting from rome. >> all right. thank you, ben. >>> a cold day to talk about global warming. thousands braved frigid temperatures on the national mall to demand action on climate change. [heart beating] [heartbeat continues] [heartbeat, music playing louder] ♪ i'm feeling better since you know me... ♪ announcer: this song was created with heartbeats of children in need. find out how it can help frontline health workers bring hope to millions